1. Technical Field
The present invention relates to a hybrid photovoltaic system which features both power grid tied operation and battery charging operation.
2. Description of Related Art
Utility networks provide an electrical power system to utility customers. The distribution of electric power from utility companies to customers utilizes a network of utility lines connected in a grid-like fashion, referred to as an power grid. The power grid may consist of many independent energy sources energizing the grid in addition to utility companies energizing the grid, with each independent energy source being referred to as a distributed power (DP) generation system. The modern utility network includes the utility power source, consumer loads, and the distributed power generation systems which also supply electrical power to the network. The number and types of distributed power generation systems is growing rapidly and can include photovoltaics, wind, hydro, fuel cells, storage systems such as battery, super-conducting flywheel, and capacitor types, and mechanical devices including conventional and variable speed diesel engines, Stirling engines, gas turbines, and micro-turbines. These distributed power generation systems are typically connected to the utility network such that they operate in parallel with the utility power sources.
The term “DC source” as used herein refers to and includes DC available from photovoltaics cells, wind powered DC generators, hydro powered turbines, fuel cells, storage systems such as battery, super-conducting flywheel, and capacitor types, and mechanical devices including conventional and variable speed diesel engines, stirling engines, gas turbines, and micro-turbines.